<?php
/* vim: set expandtab sw=4 ts=4 sts=4: */
/**
 *
 * @version $Id: zip.lib.php 10240 2007-04-01 11:02:46Z cybot_tm $
 */

/**
 * Zip file creation class.
 * Makes zip files.
 *
 * Based on :
 *
 *  http://www.zend.com/codex.php?id=535&single=1
 *  By Eric Mueller <eric@themepark.com>
 *
 *  http://www.zend.com/codex.php?id=470&single=1
 *  by Denis125 <webmaster@atlant.ru>
 *
 *  a patch from Peter Listiak <mlady@users.sourceforge.net> for last modified
 *  date and time of the compressed file
 *
 * Official ZIP file format: http://www.pkware.com/appnote.txt
 *
 * @access  public
 */
class zipfile
{
	/**
	 * Array to store compressed data
	 *
	 * @var  array	$datasec
	 */
	var $datasec	  = array();

	/**
	 * Central directory
	 *
	 * @var  array	$ctrl_dir
	 */
	var $ctrl_dir	 = array();

	/**
	 * End of central directory record
	 *
	 * @var  string   $eof_ctrl_dir
	 */
	var $eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";

	/**
	 * Last offset position
	 *
	 * @var  integer  $old_offset
	 */
	var $old_offset   = 0;


	/**
	 * Converts an Unix timestamp to a four byte DOS date and time format (date
	 * in high two bytes, time in low two bytes allowing magnitude comparison).
	 *
	 * @param  integer  the current Unix timestamp
	 *
	 * @return integer  the current date in a four byte DOS format
	 *
	 * @access private
	 */
	function unix2DosTime($unixtime = 0) {
		$timearray = ($unixtime == 0) ? getdate() : getdate($unixtime);

		if ($timearray['year'] < 1980) {
			$timearray['year']	= 1980;
			$timearray['mon']	 = 1;
			$timearray['mday']	= 1;
			$timearray['hours']   = 0;
			$timearray['minutes'] = 0;
			$timearray['seconds'] = 0;
		} // end if

		return (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) |
				($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
	} // end of the 'unix2DosTime()' method


	/**
	 * Adds "file" to archive
	 *
	 * @param  string   file contents
	 * @param  string   name of the file in the archive (may contains the path)
	 * @param  integer  the current timestamp
	 *
	 * @access public
	 */
	function addFile($data, $name, $time = 0)
	{
		$name	 = str_replace('\\', '/', $name);

		$dtime	= dechex($this->unix2DosTime($time));
		$hexdtime = '\x' . $dtime[6] . $dtime[7]
				  . '\x' . $dtime[4] . $dtime[5]
				  . '\x' . $dtime[2] . $dtime[3]
				  . '\x' . $dtime[0] . $dtime[1];
		eval('$hexdtime = "' . $hexdtime . '";');

		$fr   = "\x50\x4b\x03\x04";
		$fr   .= "\x14\x00";			// ver needed to extract
		$fr   .= "\x00\x00";			// gen purpose bit flag
		$fr   .= "\x08\x00";			// compression method
		$fr   .= $hexdtime;			 // last mod time and date

		// "local file header" segment
		$unc_len = strlen($data);
		$crc	 = crc32($data);
		$zdata   = gzcompress($data);
		$zdata   = substr(substr($zdata, 0, strlen($zdata) - 4), 2); // fix crc bug
		$c_len   = strlen($zdata);
		$fr	  .= pack('V', $crc);			 // crc32
		$fr	  .= pack('V', $c_len);		   // compressed filesize
		$fr	  .= pack('V', $unc_len);		 // uncompressed filesize
		$fr	  .= pack('v', strlen($name));	// length of filename
		$fr	  .= pack('v', 0);				// extra field length
		$fr	  .= $name;

		// "file data" segment
		$fr .= $zdata;

		// "data descriptor" segment (optional but necessary if archive is not
		// served as file)
		// nijel(2004-10-19): this seems not to be needed at all and causes
		// problems in some cases (bug #1037737)
		//$fr .= pack('V', $crc);				 // crc32
		//$fr .= pack('V', $c_len);			   // compressed filesize
		//$fr .= pack('V', $unc_len);			 // uncompressed filesize

		// add this entry to array
		$this -> datasec[] = $fr;

		// now add to central directory record
		$cdrec = "\x50\x4b\x01\x02";
		$cdrec .= "\x00\x00";				// version made by
		$cdrec .= "\x14\x00";				// version needed to extract
		$cdrec .= "\x00\x00";				// gen purpose bit flag
		$cdrec .= "\x08\x00";				// compression method
		$cdrec .= $hexdtime;				 // last mod time & date
		$cdrec .= pack('V', $crc);		   // crc32
		$cdrec .= pack('V', $c_len);		 // compressed filesize
		$cdrec .= pack('V', $unc_len);	   // uncompressed filesize
		$cdrec .= pack('v', strlen($name)); // length of filename
		$cdrec .= pack('v', 0);			 // extra field length
		$cdrec .= pack('v', 0);			 // file comment length
		$cdrec .= pack('v', 0);			 // disk number start
		$cdrec .= pack('v', 0);			 // internal file attributes
		$cdrec .= pack('V', 32);			// external file attributes - 'archive' bit set

		$cdrec .= pack('V', $this -> old_offset); // relative offset of local header
		$this -> old_offset += strlen($fr);

		$cdrec .= $name;

		// optional extra field, file comment goes here
		// save to central directory
		$this -> ctrl_dir[] = $cdrec;
	} // end of the 'addFile()' method


	/**
	 * Dumps out file
	 *
	 * @return  string  the zipped file
	 *
	 * @access public
	 */
	function file()
	{
		$data	= implode('', $this -> datasec);
		$ctrldir = implode('', $this -> ctrl_dir);

		return
			$data .
			$ctrldir .
			$this -> eof_ctrl_dir .
			pack('v', sizeof($this -> ctrl_dir)) .  // total # of entries "on this disk"
			pack('v', sizeof($this -> ctrl_dir)) .  // total # of entries overall
			pack('V', strlen($ctrldir)) .		   // size of central dir
			pack('V', strlen($data)) .			  // offset to start of central dir
			"\x00\x00";							 // .zip file comment length
	} // end of the 'file()' method

} // end of the 'zipfile' class
?>
